Senior Software Engineer (Performance)
Confirmed on the employer's own hiring board on Oct 13, 2026. First seen by Alion on Oct 8, 2026.
About the Team
The Legacy Performance Improvement team builds and maintains the systems that keep our business running. Much of our work centers on legacy platforms that power some of the company's highest-revenue projects, which means our work is visible across the organization and carries real impact. We modernize, stabilize, and extend critical systems while keeping them reliable for the teams who depend on them every day.
About the Role
We're looking for a senior engineer who is excited by the challenge of working on mature, business-critical systems and shaping how they evolve. You'll work on high-revenue, high-visibility projects, contribute to architectural decisions, mentor other engineers, and partner with stakeholders across the company to deliver tools that matter.
What You'll Do:
Design, build, and maintain internal tools and services, primarily within legacy systems
Contribute to architectural decisions, including how to incrementally modernize and improve existing platforms
Deliver on high-revenue projects where reliability, correctness, and performance are essential
Collaborate with stakeholders across engineering and the business to understand needs and communicate progress
Improve the maintainability, testing, and observability of existing codebases
Write clear technical documentation and share knowledge with the team
Participate in code reviews, mentor less-experienced engineers, and help raise the engineering bar
Who You Are (Qualifications):
5+ years of professional software engineering experience building and shipping production software
Experience with software architecture, including designing systems and making sound technical trade-offs
Comfort working in and improving legacy codebases
Strong programming fundamentals and the ability to learn new languages and tools quickly
Experience with Python
Experience building services or APIs used by other engineers or internal teams
Strong communication skills and confidence working on high-visibility projects
Experience leading or contributing to legacy system modernization or migration efforts
Familiarity with cloud infrastructure (AWS/GCP), containers, and CI/CD pipelines
Nice To Have:
What Success Looks Like (in this role):
You've shipped meaningful improvements to one of our legacy platforms and taken ownership of at least one service or component
You're contributing to architectural discussions about how these systems should evolve
Stakeholders trust you to understand their needs and deliver reliably against them
You're a dependable code reviewer and a source of sound technical judgment on the team